add block.js and tests

This commit is contained in:
Daniel Cousens 2014-10-16 15:30:57 +11:00
parent 936f7913db
commit c0c47f076a
3 changed files with 279 additions and 0 deletions

149
src/block.js Normal file
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var assert = require('assert')
var bufferutils = require('./bufferutils')
var crypto = require('./crypto')
var Transaction = require('./transaction')
var Script = require('./script')
function Block() {
this.version = 1
this.prevHash = null
this.merkleRoot = null
this.timestamp = 0
this.bits = 0
this.nonce = 0
}
Block.fromBuffer = function(buffer) {
assert(buffer.length >= 80, 'Buffer too small (< 80 bytes)')
var offset = 0
function readSlice(n) {
offset += n
return buffer.slice(offset - n, offset)
}
function readUInt32() {
var i = buffer.readUInt32LE(offset)
offset += 4
return i
}
var block = new Block()
block.version = readUInt32()
block.prevHash = readSlice(32)
block.merkleRoot = readSlice(32)
block.timestamp = readUInt32()
block.bits = readUInt32()
block.nonce = readUInt32()
if (buffer.length === 80) return block
function readUInt64() {
var i = bufferutils.readUInt64LE(buffer, offset)
offset += 8
return i
}
function readVarInt() {
var vi = bufferutils.readVarInt(buffer, offset)
offset += vi.size
return vi.number
}
function readScript() {
return Script.fromBuffer(readSlice(readVarInt()))
}
function readTransaction() {
var tx = new Transaction()
tx.version = readUInt32()
var vinLen = readVarInt()
for (var i = 0; i < vinLen; ++i) {
tx.ins.push({
hash: readSlice(32),
index: readUInt32(),
script: readScript(),
sequence: readUInt32()
})
}
var voutLen = readVarInt()
for (i = 0; i < voutLen; ++i) {
tx.outs.push({
value: readUInt64(),
script: readScript(),
})
}
tx.locktime = readUInt32()
return tx
}
var nTransactions = readVarInt()
block.transactions = []
for (var i = 0; i < nTransactions; ++i) {
var tx = readTransaction()
block.transactions.push(tx)
}
return block
}
Block.fromHex = function(hex) {
return Block.fromBuffer(new Buffer(hex, 'hex'))
}
Block.prototype.toBuffer = function(headersOnly) {
var buffer = new Buffer(80)
var offset = 0
function writeSlice(slice) {
slice.copy(buffer, offset)
offset += slice.length
}
function writeUInt32(i) {
buffer.writeUInt32LE(i, offset)
offset += 4
}
writeUInt32(this.version)
writeSlice(this.prevHash)
writeSlice(this.merkleRoot)
writeUInt32(this.timestamp)
writeUInt32(this.bits)
writeUInt32(this.nonce)
if (headersOnly || !this.transactions) return buffer
function varIntBuffer(i) {
var ib = new Buffer(bufferutils.varIntSize(i))
bufferutils.writeVarInt(ib, i, 0)
return ib
}
var txLenBuffer = varIntBuffer(this.transactions.length)
var txBuffers = this.transactions.map(function(tx) {
return tx.toBuffer()
})
return Buffer.concat([buffer, txLenBuffer].concat(txBuffers))
}
Block.prototype.toHex = function(headersOnly) {
return this.toBuffer(headersOnly).toString('hex')
}
Block.prototype.getId = function() {
return bufferutils.reverse(this.getHash()).toString('hex')
}
Block.prototype.getHash = function() {
return crypto.hash256(this.toBuffer(true))
}
module.exports = Block

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test/block.js Normal file
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var assert = require('assert')
var Block = require('../src/block')
var fixtures = require('./fixtures/block')
describe('Block', function() {
describe('fromBuffer/fromHex', function() {
fixtures.valid.forEach(function(f) {
it('imports the block: ' + f.description + ' correctly', function() {
var block = Block.fromHex(f.hex)
assert.equal(block.version, f.version)
assert.equal(block.prevHash.toString('hex'), f.prevHash)
assert.equal(block.merkleRoot.toString('hex'), f.merkleRoot)
assert.equal(block.timestamp, f.timestamp)
assert.equal(block.bits, f.bits)
assert.equal(block.nonce, f.nonce)
})
})
fixtures.invalid.forEach(function(f) {
it('throws on ' + f.exception, function() {
assert.throws(function() {
Block.fromHex(f.hex)
}, new RegExp(f.exception))
})
})
})
describe('toBuffer/toHex', function() {
fixtures.valid.forEach(function(f) {
var block
beforeEach(function() {
block = Block.fromHex(f.hex)
})
it('exports the block: ' + f.description + ' correctly', function() {
assert.equal(block.toHex(), f.hex)
})
})
})
describe('getHash', function() {
fixtures.valid.forEach(function(f) {
var block
beforeEach(function() {
block = Block.fromHex(f.hex)
})
it('calculates ' + f.hash + ' for the block: ' + f.description, function() {
assert.equal(block.getHash().toString('hex'), f.hash)
})
})
})
describe('getId', function() {
fixtures.valid.forEach(function(f) {
var block
beforeEach(function() {
block = Block.fromHex(f.hex)
})
it('calculates ' + f.id + ' for the block: ' + f.description, function() {
assert.equal(block.getId(), f.id)
})
})
})
})

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test/fixtures/block.json vendored Normal file

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